CFD Performance Evaluation and Runner Blades Design Optimization in a Francis Turbine

2009 ◽  
Author(s):  
Jose Manuel Franco-Nava ◽  
Erik Rosado-Tamariz ◽  
Oscar Dorantes-Gomez ◽  
Jose´ Manuel Ferna´ndez-Da´vila ◽  
Reynaldo Rangel-Espinosa
Keyword(s):  
Measurement System ◽  
Three Dimensional ◽  
Hydrodynamic Performance ◽  
Francis Turbine ◽  
Computational Domain ◽  
Coordinate Measurement ◽  
Spiral Case ◽  
Hydraulic Turbines ◽  
Optimization Methodology ◽  
Artificial Neural Network Ann

The application of computational fluid dynamics (CFD) in the redesign or rehabilitation of hydraulic turbines appears to be necessary in order to improve their efficiency and cost-effectiveness beyond the traditional redesign practices. The runner geometry considered within the computational domain was modelled by using a three-dimensional laser triangulation scanner coupled with a portable coordinate measurement system. The runner geometry was generated by a number of 3D sub models, one for each of the main components of the runner, crown, band and a blade. In order to obtain a blade geometry a portable coordinate measurement system based on optical digitalization technology (scanner technology) was used. A numerical optimization methodology is developed and applied to a Francis turbine. The hydrodynamic performance analysis was investigated by application of a three dimensional Navier-Stoke commercial turbomachinery oriented CFD code. Analysis of the flow through the spiral case and stay vanes was carried out so as to include appropriate flow effects induced by these components and boundary conditions at the inlet of the wicket. A CFD analysis for the wicket and runner was carried out to generate the so called reference solution. Then, the runner blades design was optimized by a process implemented in a commercial CFD code which combines genetic algorithms and a trained artificial neural network (ANN). A database of geometries and their respective CFD computations were computed in order to determine the optimum geometry for a given objective function. The flow within hydraulic turbines has a thin boundary layer and noticeable pressure gradients. Hence, the CFD computations were carried out using the Sparlat-Allmaras turbulence model. After optimization cycle convergence, an increment not only in efficiency but also in power was obtained. The optimized runner represented by a parametric model achieves considerably higher efficiency than the reference runner. Efficiency versus power curve was used to compare data from measurements at the power station for the reference runner versus the parametric optimized runner model. Results have shown that application of CFD based optimization can modify and improve runners design so as to increase the efficiency and power of installed hydraulic power stations.

Flow Induced Stresses in a Francis Turbine Runner Using Computer-Based Design Tools

2009 ◽  
Author(s):  
Jose´ Manuel Franco-Nava ◽  
Oscar Dorantes-Go´mez ◽  
Erik Rosado-Tamariz ◽  
Jose´ Manuel Ferna´ndez-Da´vila ◽  
Reynaldo Rangel-Espinosa
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Francis Turbine ◽  
Computational Domain ◽  
Element Analysis ◽  
Coordinate Measurement ◽  
The Finite Element Analysis ◽  
Turbine Runner ◽  
Induced Stresses

The stress analysis of the runner due to different loading is one of the most important tools that contribute its structural integrity evaluation. Finite element method has shown to be a strong numerical technique to provide good engineering accuracy. In this paper, the flow induced stresses in a Francis turbine runner is presented by using the finite element analysis. The runner geometry considered within the computational domain was modelled by using a three-dimensional laser triangulation scanner coupled with a portable coordinate measurement system. The runner geometry was generated by a number of 3D sub models, one for each of the main components of the runner, crown, band and a blade. In order to obtain a blade geometry a portable coordinate measurement system based on optical digitalization technology (scanner technology) was used. Because of symmetry, only a section of the runner domain was used for the finite element analysis. The runner was modeled with twenty-node solid elements. Loads due to pressure on the blade were derived from CFD computations for the runner at different power conditions (100%, 85% and 75%) for a medium head hydro power plant. CFD computations were carried out using the Finite Volume Method implement within FINE™/Turbo by NUMECA. The turbulence mathematical model used for the CFD computation was the Sparlart-Allmaras. The mesh of the turbine runner included different computational domains. For the runner blades the computational domain (mesh block) was defined in order to capture the complete blade row. All mesh blocks were structured hexahedral. Centrifugal force based on the rotational speed was considered. Also, a combined type loading analysis was computed including both pressure and centrifugal force. Appropriate boundary conditions were set in order to obtain the results due to the different type of analysis. The number of finite elements included in the FEM model was able to capture the pressure gradients on the blade surfaces obtained from the CFD results, which were investigated by application of a three dimensional Navier-Stoke commercial turbomachinery oriented CFD code. Analysis of the flow through the spiral case and stay vanes was carried out so as to include appropriate flow effects induced by these components and boundary conditions at the inlet of the wicket. A CFD analysis for the wicket and runner was carried out to generate the so called CFD reference solution. The analysis presented in this paper represents an initial characterization in order to increase understanding about combined loads acting on blades and to establish a reference state of stresses further comparison after refurbishments or optimization of the runner blades for a medium head hydroelectric power station.

Research on the influence of background light on the accuracy of a three-dimensional coordinate measurement system based on dual-PSD

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Xiaohong Lu ◽  
Yu Zhou ◽  
Jinhui Qiao ◽  
Yihan Luan ◽  
Yongquan Wang
Keyword(s):  
Neural Network ◽  
Measurement System ◽  
Bp Neural Network ◽  
Measurement Accuracy ◽  
Three Dimensional ◽  
Electrical Method ◽  
Content Type ◽  
Coordinate Measurement ◽  
Background Light ◽  
Three Dimensional Coordinate

Purpose The purpose of this paper is to analyze the measurement error of a three-dimensional coordinate measurement system based on dual-position-sensitive detector (PSD) under different background light. Design/methodology/approach The mind evolutionary algorithm (MEA)-back propagation (BP) neural network is used to predict the three-dimensional coordinates of the points, and the influence of the background light on the measurement accuracy of the three-dimensional coordinates based on PSD is obtained. Findings The influence of the background light on the measurement accuracy of the system is quantitatively calculated. The background light has a significant influence on the prediction accuracy of the three-dimensional coordinate measurement system. The optical method, electrical method and photoelectric compensation method are proposed to improve the measurement accuracy. Originality/value BP neural network based on MEA is applied to the coordinate prediction of the three-dimensional coordinate measurement system based on dual-PSD, and the influence of background light on the measurement accuracy is quantitatively analyzed.

Four Quadrants Numerical Prediction for Hydrodynamic Performance of Open-Water Propeller

2010 ◽  
Vol 143-144 ◽  
pp. 1143-1147
Author(s):  
Bing Xiao ◽  
Xiao Wang ◽  
Ai Guo Shi ◽  
Ming Wu
Keyword(s):  
Three Dimensional ◽  
Open Water ◽  
Mathematic Model ◽  
Hydrodynamic Performance ◽  
Computational Domain ◽  
Basic Parameters ◽  
Tank Test ◽  
Open Water Performance ◽  
Thrust And Torque ◽  
Good Agreement

In order to obtain the four quadrants hydrodynamic performance of open water propeller by means of CFD, a mathematic model of three dimensional coordinates points was established and programmed using Matlab based on the basic parameters of propeller. A smooth model propeller was made by importing these points into front end software. Then taking AU model for example, numerical simulations of propeller turning ahead while going ahead, turning ahead while going astern, turning astern while going ahead and turning astern while going astern were carried out. At the same time, the thrust and torque coefficients were presented. The simulation results showed good agreement with the results of tank test. The influence of mesh generation and computational domain on open-water performance were also discussed.

Optimal Layout of Three-Dimensional Coordinate Measurement System Based on Laser Multi-Lateration

2014 ◽  
Vol 41 (7) ◽  
pp. 0708001
Author(s):  
胡进忠 Hu Jinzhong ◽  
余晓芬 Yu Xiaofen ◽  
任兴 Ren Xing ◽  
赵达 Zhao Da
Keyword(s):  
Measurement System ◽  
Three Dimensional ◽  
Optimal Layout ◽  
Coordinate Measurement ◽  
Three Dimensional Coordinate

Hydraulic turbines—basic principles and state-of-the-art computational fluid dynamics applications

1999 ◽  
Vol 213 (1) ◽  
pp. 85-102 ◽  
Author(s):  
P Drtina ◽  
M Sallaberger
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
State Of The Art ◽  
Three Dimensional ◽  
Hydraulic Turbine ◽  
Francis Turbine ◽  
Basic Principles ◽  
Vast Number ◽  
Basic Fluid ◽  
Hydraulic Turbines

The present paper discusses the basic principles of hydraulic turbines, with special emphasis on the use of computational fluid dynamics (CFD) as a tool which is being increasingly applied to gain insight into the complex three-dimensional (3D) phenomena occurring in these types of fluid machinery. The basic fluid mechanics is briefly treated for the three main types of hydraulic turbine: Pelton, Francis and axial turbines. From the vast number of applications where CFD has proven to be an important help to the design engineer, two examples have been chosen for a detailed discussion. The first example gives a comparison of experimental data and 3D Euler and 3D Navier-Stokes results for the flow in a Francis runner. The second example highlights the state-of-the-art of predicting the performance of an entire Francis turbine by means of numerical simulation.

Layout Optimization of Three-Dimensional Coordinate Measurement System Based on Laser Multi-Lateration

2014 ◽  
Vol 41 (1) ◽  
pp. 0108006
Author(s):  
胡进忠 Hu Jinzhong ◽  
余晓芬 Yu Xiaofen ◽  
彭鹏 Peng Peng ◽  
黄开辉 Huang Kaihui
Keyword(s):  
Measurement System ◽  
Three Dimensional ◽  
Layout Optimization ◽  
Coordinate Measurement ◽  
Three Dimensional Coordinate

A Review of Available Methods for the Assessment of Fluid Added Mass, Damping, and Stiffness With an Emphasis on Hydraulic Turbines

2018 ◽  
Vol 70 (5) ◽  
Author(s):  
Arash Soltani Dehkharqani ◽  
Jan-Olov Aidanpää ◽  
Fredrik Engström ◽  
Michel J. Cervantes
Keyword(s):  
Three Dimensional ◽  
Added Mass ◽  
Literature Survey ◽  
Francis Turbine ◽  
Three Dimensional Flow ◽  
Experimental Approaches ◽  
Complex Fluid ◽  
Hydraulic Turbines ◽  
The Impact ◽  
Fluid Added Mass

Fluid added mass, damping, and stiffness are highly relevant parameters to consider when evaluating the dynamic response of a submerged structure in a fluid. The prediction of these parameters for hydraulic turbines has been approached relatively recently. Complex fluid-structure analyses including three-dimensional flow and the need for experiments during operation are the main challenges for the numerical and experimental approaches, respectively. The main objective of this review is to address the impact of different parameters, for example, flow velocity, cavitation, nearby solid structure, and rotational speed on the fluid added mass and damping of Kaplan/Propeller and Francis turbine runners. The fluid added stiffness is also discussed in the last section of the paper. Although studies related to hydraulic turbines are the main objective of this paper, the literature on hydrofoils is also taken into consideration to provide valuable information on topics such as individual runner blades. In this literature survey, the analytical, numerical, and experimental approaches used to determine fluid added parameters are discussed, and the pros and the cons of each method are addressed.

A Three-dimensional Camera: Development and Applications of a Three-dimensional Image Measurement System

2011 ◽  
Vol 131 (2) ◽  
pp. 320-328 ◽  
Author(s):  
Cunwei Lu ◽  
Hiroya Kamitomo ◽  
Ke Sun ◽  
Kazuhiro Tsujino ◽  
Genki Cho
Keyword(s):  
Measurement System ◽  
Three Dimensional ◽  
Image Measurement ◽  
Dimensional Image

A comparative study and combined application of RSM and ANN in adsorptive removal of diuron using biomass ashes

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sunil K. Deokar ◽  
Nachiket A. Gokhale ◽  
Sachin A. Mandavgane
Keyword(s):  
Three Dimensional ◽  
Current Approach ◽  
Coefficient Of Determination ◽  
Ann Model ◽  
Operational Parameters ◽  
Initial Concentration ◽  
Combined Application ◽  
Artificial Neural Network Ann ◽  
Relationship Of ◽  
Biomass Ashes

Abstract Biomass ashes like rice husk ash (RHA), bagasse fly ash (BFA), were used for aqueous phase removal of a pesticide, diuron. Response surface methodology (RSM) and artificial neural network (ANN) were successfully applied to estimate and optimize the conditions for the maximum diuron adsorption using biomass ashes. The effect of operational parameters such as initial concentration (10–30 mg/L); contact time (0.93–16.07 h) and adsorbent dosage (20–308 mg) on adsorption were studied using central composite design (CCD) matrix. Same design was also employed to gain a training set for ANN. The maximum diuron removal of 88.95 and 99.78% was obtained at initial concentration of 15 mg/L, time of 12 h, RHA dosage of 250 mg and at initial concentration of 14 mg/L, time of 13 h, BFA dosage of 60 mg respectively. Estimation of coefficient of determination (R 2) and mean errors obtained for ANN and RSM (R 2 RHA = 0.976, R 2 BFA = 0.943) proved ANN (R 2 RHA = 0.997, R 2 BFA = 0.982) fits better. By employing RSM coupled with ANN model, the qualitative and quantitative activity relationship of experimental data was visualized in three dimensional spaces. The current approach will be instrumental in providing quick preliminary estimations in process and product development.

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